@b!z: Good pickup, haven't laughed so hard in a while. Now that I think about it, I sense rather than actually wanting to advertise, OP is simply mocking the idea of selling his sig space rather than actually doing it.
Yep, no one has taken the offer of $5000/day yet.
No one would take that offer. Ads Signatures did contribute to the forum in some way. Many members want their business to got known and other members who don't have bitcoin that no other means to obtain them has a chance now to earn a little bitcoin for their work. It bring new adopters to bitcoin. Not all posts is spam don't generalize.